QUESTION: hi sir..
i am a general dentist....
i frequently fail to achieve anesthesia...during root canal...for that reason i place pulp x or formocresol as devitalizing work for some in 2 days of recall and recently i have to do this thrice...i try local anesthesia with 2% xylocaine but failed.. sometime i repeat application for chamber pulp and canal pulp...where can be mistake...what can be done...

ANSWER: Hi Ritu,

There is nothing more frustrating for us dentists then not having good anesthesia. When I do root canals on vital teeth that have been VERY sensitive to temperature, maybe even acutely, I start by testing my anesthesia by putting ice on the tooth to make sure the patient is numb and not feeling anything cold. If all the lip signs are there (feeling like the lip is fat)and the patient feels the cold, then you know you need supplemental anesthesia.

The first thing I try is to give injections through the periodontal ligament. I use a Ligmajet. Here is a picture:

The wand is also helpful in some cases.

Then I check with ice again and re-inject if cold is still felt. If the problems occurs as you enter the pulp, then I inject directly into the pulp. My experience with formocresol is the same as works sometimes, but is not predictable.

The combination of all these things will 100% of the time get patients numb enough to complete your treatment.

I hope this helps you solve your problem. Good luck! Write back if you have more questions...

Gary Backlund DMD, MSD

---------- FOLLOW-UP ----------

QUESTION: thanks sir...
intraplpal injection is very painful...isn't so!!
i used it twice....after that patient complains that it will be better if i do extraction...
can intrapulal injection can be made comfortable!!!

Hi again Ritu,

Yes, you are right. The way I do it is better, but can still be quite painful for a second or two. I start by dropping some anesthetic on the area I plan to inject. Leave it for 10-20 seconds, then as I insert the needle, I also inject. The pressure seems to help so it is not as painful. I have also found most patients, if you explain what you are going to do and why would rather have a short painful experience rather than several appointments with unsuccessful anesthesia. I think it is really a tradeoff of options, but you are certainly correct.

I would suggest that the next time you have this trouble, you talk with the patient and see which option they choose....quick, but possibly painful intra pulpal or come back and try again with injections to get numb etc.

I also rarely have this problem anymore since I use the Ligamajet. It has really helped with getting the extra numbness we both need from time to time.

Best of luck!

Gary Backlund DMD, MSD


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Gary Backlund, DMD, MSD


I am an Endodontist ( root canal specialist ) and can answer questions about root canals and their treatment. I cannot diagnose or treat online, but can answer general questions. I have been a specialist for 25 years and am Past President of the Washington State Association of Endodontists.


25 years practicing as a specialist

American Association of Endodonists, Past President Washington State Association of Endodontists.

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